rx10 wrote:
Oh! Wow. Nice question.
We are given that \(a=-1\) & \(\frac{a-b}{c}=1\)
Now
for \(\frac{a-b}{c}=1\) , the numerator cannot be \(0\)
\(a - b ≠ 0\)
\(-1-b ≠ 0\)
\(b ≠ -1\)
Answer B
The denominator cannot be 0. The bottom part of the fraction because otherwise would be an indefinite fraction which is impossible on the GRE
Quote:
In this case, c can’t equal zero, so whatever value
is impossible for b must be the one that corresponds to c = 0.
To simplify the expression, multiply by c:
a − b = c
If a = −1, then −1 − b = c, or b = −c − 1. If c = 0, then b = −0 − 1 = −1.
So, since c cannot equal zero, b cannot equal -1, choice (B).